What does this mean: independent or embedded?

You are using a piece of open source software as an embedded component of a larger unit if [a] one of your files of the larger unit contains a verbatim or a modified copy (i.e. a snippet) of the received open source software, or [b] if your larger unit contains an include statement referring to a functionally defining file of the received open source software, or [c] if your larger unit calls a function defined in the received open source software, or [d] if your development environment contains a compiler or linker directive referring to the received open source software (binaries) and if your larger unit can't be executed without resolving this linker directive.

On the opposite, if you are using an open source application [proapse] (which can directly be executed by your operating system or by an interpreter) or if you are distributing an open source snippet, module or library without embedding it into a larger 'on-top application', then you are using this piece of open source software independendly.

So, we can say that ...

an application is used independendly per definition.

often open source distributions contain libraries which are not used by one of its applications, but are offered to the software developer - so the distributor is using this library independly